Contact printing apparatus

ABSTRACT

Improved printing apparatus having a tiltable printing frame with a first light source for use when the printing frame is in a horizontal position and a second light source for use when the printing frame is in a vertical position and apparatus to automatically deenergize the first light source and energize the second light source and further apparatus to automatically position the second light source.

Edited States Patent Bradley et al.

[54] CONTACT PRINTING APPARATUS [72] Inventors: Thomas E. Bradley,Bethlehem; galter Spadt, Jr., Emmaus, both of Assignee: Bethlehem SteelCorporation Filed: Oct. 28, 1971 Appl. No.: 193,408

US. Cl. ..355/120, 355/93, 355/120 lnt. Cl. ..G03b 27/04 Field of Search.......355/93, 120

[56] References Cited UNITED STATES PATENTS 2,210,726 8/1940 Mazzocco..355/93x [15] 3,682,551 [451 Aug. 8, 1972 2,534,784 12/1950 Maxwell..355/93 X 2,534,794 12/1950 Powers, Sr. ..355/93 X 3,106,145 10/1963Hutchins ..355/93 Primary Examiner-Samuel S. Matthews AssistantExaminer-Richard M. Sheer Attorney-Joseph .l. OKeefe [5 7] ABSTRACTImproved printing apparatus having a tiltable printing frame with afirst light source for use when the printing frame is in a horizontalposition and a second light source for use when the printing frame is ina vertical position and apparatus to automatically deenergize the firstlight source and energize the second light source and further apparatusto automatically position the second light source.

6 Claim, 3 Drawing Figures PATENTED 9 C I J 4 I INVENTORS Thomas EBradley B Walter Spad/ Jr.

7 rrouzv 1 CONTACT PRINTING APPARATUS BACKGROUND OF THE INVENTION Thisinvention relates generally to contact printing apparatus and moreparticularly to an improved dual purpose exposure unit.

Recent developments in photosensitive material provide a fast, goodquality method of instant image proofing. Existing equipment, however,is not readily adaptable to use with the instant image proofingphotosensitive material. Most commercial equipment, rollthrough or otherexposure units are not dual purpose, being limited to standardoperations such as exposing composite negatives wherein the light sourceis a quartz lamp. The recently developed photosensitive material isexposed to ultra violet cool light source employing 1 volts.

It is an object of this invention therefore to provide a dual-purposeunit capable of use in standard proofing operation and instant imageproofing operation.

It is a further object of the invention to provide automatic switchingmeans between the operations.

It is a still further object of the invention to automatically positionthe light source in the instant image proofing operation.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is aside elevational view of the equipment showing the apparatus in oneposition of operation;

FIG. 2 is a view similar to FIG. 1 but with parts removed to expose moreclearly details of the invention showing the apparatus in an alternateposition; and

FIG. 3 is a schematic wiring diagram.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the FIGURES,the contact printing apparatus 10 of the instant invention is seen togenerally comprise a frame or support structure 11, a printing frame 12pivotable about pivot point 13, first light source 14, second lightsource 15 and carriage 16. The support structure 11 includes a frame 17which is mounted thereon and extends to the rear therefrom.

The first light source 14, e.g. a quartz lamp, is used when the printingframe 12 is in a horizontal position for use in standard ofisetprocedures. The second light source 15 comprises a bank of 12 closelyspaced ultra violet tubes mounted on a sheet of plywood covered withsheet asbestos and reflective aluminum foil. The aluminum foil isgrounded to encourage proper ionization of the gas in the tubes. Sheetmetal housing 26 prevents stray ultra violet rays from emitting into theroom. The second light source 15 is used when the printing frame 12 ispivoted to a vertical position as shown in FIG. 2. The bank of lights oflight source 15 is bracketed to a set of rollers 18 riding in twinchannels 19 pennitting second light source 15 to move toward or awayfrom the printing frame 12.

Printing frame 12 which as shown is of conventional design, including aglass frame 21 and blanket frame 22, has cam follower means 23 mountedat the rear thereof on either side, the purpose for which will bepresently described.

Pneumatic damper 24 is mounted on frame 17 and is connected to carriage16 to provide the power to move carriage 16 toward the printing frame 12under pneumatic action similar to a door check. The pneumatic damper 24also provides a damping effect to the movement of the carriage 16 toprevent jarring of the bank of ultra violet tubes of light source 15 andconsequent damage thereto as will be understood from the description ofthe operation of the apparatus.

Referring now to FIG. 3 which shows a schematic wiring diagram of theelectrical control system for the automatic operation of the equipmentwhen the printing frame 12 is in a horizontal position. The electricalcontrol system is seen to generally comprise v supply, on-off switch 30,timer or exposure control means 31, first limit switch 33, second ormaster limit switch 32, including contacts 32a and 32b, first lightsource 14 and second light source 15. All components are wired into thesystem through junction box 35 of FIG. 1. Limit switch 33 located at thefront of support structure 11 is actuated when the printing frame 12 islaid down in the horizontal position, the contacts of limit switch 33being closed when the switch is depressed by the weight of the printingframe 12 resting on it. Master limit switch 32 is located at the rear ofsupport structure 11 and mounted thereon to be activated when theprinting frame 12 is pivoted to the vertical position. As will beunderstood by subsequent description herein, the arrangement of limitswitches permits the deenergization of one light source while the otherlight source is energized, thus conveniently providing a dual purposeexposure unit.

In operation: the contact printing apparatus 10 of the instant inventionas hereinbefore described is a dual purpose exposure machine. Theprinting frame 12 located in the horizontal position as seen in solidlines in FIG. I is used for standard ofiset procedures and a first lightsource 14, e.g., a quartz lamp, is provided for exposure purposes. Timer31 is also connected in the system as seen in FIG. 3 and is manually setto provide a timed exposure of said first light source 14 and saidsecond light source 15.

The exposure of instant image proofing photosensitive material to asecond light source 15, e.g., a bank of 110 V ultra violet tubes, isaccomplished by tilting the printing frame 12 about pivot point 13 to avertical position. The cam followers 23 mounted on the printing frame 12at the rear thereof are in contact with the housing 26 of the bank oflights of second light source 15 when the printing frame is in thehorizontal position and thus space the second light source 15 to therear of the printing frame 12 when the printing frame is horizontallydisposed. As the printing frame 12 is tilted or pivoted to the verticalposition the cam followers 23 roll down wear plate 27 mounted on theface of the housing 26 until they are free from contact with the bank oflights of light source 15 intermediate the horizontal and verticalpositions of the printing frame 12 as seen in phantom lines in FIG. I.The printing frame will continue rotation about pivot point 13 until ithas reached the vertical position.

The bank of lights 15 mounted on carriage 16 is advancedby the pneumaticdamper 24 toward the now vertical printing frame 12 until contact ismade once again with the cam followers 23 which act as a stop and spacethe bank of lights from the printing frame the desired distance as shownin FIG. 2. During the short time while the cam followers 23 mounted onthe rear of printing frame 12 are free from contact with wear plate 27of housing 26 the carriage 16 is under the control of pneumatic damper24 and is biased toward the vertically disposed printing frame 12 onrollers 18 and twin channels 19. Pneumatic damper 24 is normally fullyextended by the force of the cam followers 23 against the bank of lights15 when the printing frame 12 is horizontal. The printing frame 12 isreleased from contact with wear plate 27 of housing 26 of the lightsource 15 as the cam followers 23 rotate about an arc described aboutpivot point [3 as a center.

The damping effect of pneumatic damper 24 hereinbefore referred tocontrols the movement of carriage 16 toward the printing frame 12 sothat as the printing frame 12 is raised toward a vertical position theprinting frame 12'becomes separated from wear plate 27 of housing 26 ofthe light source 15 for a time to allow the printing frame to reach itsvertical position before contact is made again between theaforementioned printin g frame and wear plate. The cam followers 23 actas a stop for the movement of the carriage 16 against the verticallydisposed printing frame 12. The damping effect prevents jarring of thebank of lights of second light source 15.

When the printing frame 12 is in a vertical position, the bank oflightsof light source 15 is spaced about 3 inches from the face of theprinting frame 12. This space can be adjusted as desired by moving thecam followers 23 or installing a stop (not shown) between support 11 andhousing 26, as desired. Metal housing 26 provides means to prevent theemission of stray ultra violet light from around the periphery of theprinting frame 12.

Referring to FIGS. 1 and 3 for a detailed description of the switchingarrangement it is presumed that the printing frame 12 is laid down inthe horizontal position for exposure to the first light source .14. Theon-off switch 30 connected to the 1 V power source is actuated and timer31 which is normally open (NO) is manually set by the operator to thedesired exposure time. The limit switch 33 is actuated by virtue ofcontact made by the horizontally disposed printing frame 12 thus closingthe contacts in limit switch 33 to energize the quartz lamp or firstlight source 14. It is understood that contacts 32a are closed.

Master limit switch 32 is designed so that when the printing frame 12 ispivoted to a vertical position for instant image proofing and contact ismade between the limit switch 32 and the rearrnost portion of theprinting frame 12 as seen in FIG. 2, contacts 32a are opened andcontacts 32b are closed thus energizing the plurality of ultra violettubes a to 15n inclusive when the timer 31 is set. The contacts in limitswitch 33 are opened immediately upon release of the horizontallydisposed printing frame 12 from contact therewith when pivoting theframe 12 toward the vertical position, thus deenergizing first lightsource 14. Second light source 15 is energized as described above whenthe printing frame 12 reaches the vertical position and the timer isset. I

We claim:

1. In contact printing apparatus having a support structure, a printingframe pivotally mounted on said support structure for movement between ahorizontal and a vertical position'and a first light source for use withsaid printing frame when said printing frame is in the horizontalposition, the improvement comprising:

a. a second light source for use when said printing frame is in thevertical position,

b. means on said support structure to automatically position said secondlight source relative to said printing frame when said printing frame ispivoted to the vertical position, and

c. means on said support structure to automatically energize anddeenergize said first light source only when said printing frame is inthe horizontal position and said second light source only when saidprinting frame is in the vertical position.

2. Contact printing apparatus according to claim 1 wherein the meansdescribed in subparagraph (b) comprises a pneumatic damper mounted onsaid second light source to move said second light source horizontallytoward said printing frame when said printing frame is in the verticalposition.

3. Contact printing apparatus according to claim 1 wherein the meansdescribed in subparagraph (c) comprises first and second limit switchesactivated by movement of said printing frame, and a timer.

4. Contact printing apparatus according to claim 1 wherein the meansdescribed in subparagraph (b) comprises a pneumatic damper mounted onsaid support structure and connected to said second light source to movesaid second light source toward said printing frame when said printingframe is in the vertical position, and the means described insubparagraph (c) comprises a first limit switch activated by pivotingsaid printing frame above the horizontal position to deenergize saidfirst light source, and

a second limit switch activated by pivoting said printing frame to avertical position to energize said second light source,

5. Contact printing apparatus according to claim 1 wherein the meansdescribed in subparagraph (b) comprises a carriage supporting saidsecond light source mounted on said support structure for movementtoward and away from said printing frame,

cam followers mounted on said printing frame in rolling contact withsaid carriage, and a pneumatic damper mounted on said support structureand connected to said carriage to move said carriage toward saidprinting frame when said printing frame is raised.

6. Contact printing apparatus according to claim 5 wherein the meansdescribed in subparagraph (c) comprises a first limit switch activatedby pivoting said printing frame above the horizontal position todeenergize said first light source, and

a second limit switch activated by pivoting said printing frame to avertical position.

1. In contact printing apparatus having a support structure, a printingframe pivotally mounted on said support structure for movement between ahorizontal and a vertical position and a first light source for use withsaid printing frame when said printing frame is in the horizontalposition, the improvement comprising: a. a second light source for usewhen said printing frame is in the vertical position, b. means on saidsupport structure to automatically position said second light sourcerelative to said printing frame when said printing frame is pivoted tothe vertical position, and c. means on said support structure toautomatically energize and deenergize said first light source only whensaid printing frame is in the horizontal position and said second lightsource only when said printing frame is in the vertical position. 2.Contact printing apparatus according to claim 1 wherein the meansdescribed in subparagraph (b) comprises a pneumatic damper mounted onsaid second light source to move said second light source horizontallytoward said printing frame when said printing frame is in the verticalposition.
 3. Contact printing apparatus according to claim 1 wherein themeans described in subparagraph (c) comprises first and second limitswitches activated by movement of said printing frame, and a timer. 4.Contact printing apparatus according to claim 1 wherein the meansdescribed in subparagraph (b) comprises a pneumatic damper mounted onsaid support structure and connected to said second light source to movesaid second light source toward said printing frame when said printingframe is in the vertical position, and the means described insubparagraph (c) comprises a first limit switch activated by pivotingsaid printing frame above the horizontal position to deenergize saidfirst light source, and a second limit switch activated by pivoting saidprinting frame to a vertical position to energize said second lightsource,
 5. Contact printing apparatus according to claim 1 wherein themeans described in subparagraph (b) comprises a carriage supporting saidsecond light source mounted on said support structure for movementtoward and away from said printing frame, cam followers mounted on saidprinting frame in rolling contact with said carriage, and a pneumaticdamper mounted on said support structure and connected to said carriageto move said carriage toward said printing frame when said printingframe is raised.
 6. Contact printing apparatus according to claim 5wherein the means described in subparagraph (c) comprises a first limitswitch activated by pivoting said printing frame above the horizontalposition to deenergize said first light source, and a second limitswitch activated by pivoting said printing frame to a vertical position.